A helicopter fault, which can be caused by either a misadjustment or a worn or broken component, will generally manifest itself as excessive helicopter vibrations. Excessive vibrations can also cause other faults and can contribute to crew fatigue. Therefore, it is desirable to find the source of the vibrations and remedy the problem.
A maintenance crew can eliminate excessive vibrations by replacing and/or adjusting all of the components which might be a possible cause. However, this method will increase maintenance time for the helicopter. Furthermore, since all of the possible components which could explain the vibrations are replaced, this method will needlessly deplete spare parts stores.
The maintenance crew may employ the procedure outlined in Army Maintenance Manual #TM55-1520-237-23-7, wherein an excessive vibration source is isolated using a plurality of accelerometers, attached at various locations throughout the helicopter, to measure vibrations. However, aircraft vibrations sometimes have complex interactions which make the process of determining the correct set of adjustments and/or component replacements time consuming and which therefore may require numerous expensive test flights.